The Administrative Core will serve as the headquarters for the SCOR: Sex Differences and Progesterone Effects on Impulsivity, Smoking, &Cocaine abuse. Drs. Marilyn E. Carroll and Sharon Allen will serve as Co- Directors of the SCOR using a Multiple PI Leadership Plan. The Department of Psychiatry and the Academic Health Center will provide ample space for SCOR staff and the operating procedures. In addition, the Delaware Clinical Research Unit and the Ambulatory Research Center are available for interview and testing space. Administrative Core A will provide the administrative service and coordinate the other Cores, Training and Service (B) and Statistics (C) to benefit the research and training goals of the three projects.